This research focuses on the social influence processes that appear to underly the development of teenage smoking. Questionnaire data suggests that the first cigarette usually occurs in the presence of others and those others are typically peers. Moreover, much of the variance in smoking rate among teens is accounted for by the smoking of the teenagers' parents and friends. However, data on the specific processes that underly these relationships are lacking. Studies rely almost entirely on uncorroborated questionnaire responses. They do not provide use with a taxonomy of the situations in which early smoking is likely to occur. And, they do not tell us about more and less skillful ways in which young people might cope with these situations. The proposed research is a response to these gaps in our knowledge and is divided into four components. Component I is designed to identify in detail the influences that prompt young people to smoke. It employs interview methods and daily records of influence situations in addition to the usual questionnaire and physiological methods. While it is open to the discovery of nonsocial factors that prompt young people to smoke, Component I is primarily aimed at social influences. Component II involves the direct observation of teenagers smoking and social behavior in public settings. It is designed to corroborate some of the findings in Component I and test the hypothesis that others' social behavior functions to prompt smoking, even when no overt pressure is applied. In Component III, we will develop role-play assessments of the social influences surrounding smoking. This study will contribute to our knowledge of the social behavior relevant to smoking, while at the same time addressing some important methodological problems concerning the validity of such assessment procedures. Component IV provides a test of a curriculum for smoking prevention that we propose to build on the basis of Components I, II, and III.